---
id: 655790d113d14dbb727eaf41
title: Passo 40
challengeType: 20
dashedName: step-40
---

# --description--

Once the distance to a node is set inside the `distances` dictionary, you need to keep track of the path to that node, too. If the distance for the node in the processed tuple has been updated, the last item in its path is the node itself.

Inside your conditional, nest another `if` statement that triggers when the last element of `paths[node]` is equal to `node`.

# --hints--

You should create a nested `if` statements that checks if `paths[node][-1]` is equal to `node`. Don't forget to use `pass`.

```js
({ test: () =>  {
    const shortest = __helpers.python.getDef(code, "shortest_path");
    const {function_body} = shortest;    
    assert(function_body.match(/^(\s*)if.*:.*^\1(\s{4})if\s+paths\s*\[\s*node\s*\]\s*\[\s*-\s*1\s*\]\s*==\s*node\s*:\s*^\1\2\2pass/ms));
  }
})
```

# --seed--

## --seed-contents--

```py
my_graph = {
    'A': [('B', 3), ('D', 1)],
    'B': [('A', 3), ('C', 4)],
    'C': [('B', 4), ('D', 7)],
    'D': [('A', 1), ('C', 7)]
}

def shortest_path(graph, start):
    unvisited = list(graph)
    distances = {node: 0 if node == start else float('inf') for node in graph}
    paths = {node: [] for node in graph}
    paths[start].append(start)
--fcc-editable-region--    
    while unvisited:
        current = min(unvisited, key=distances.get)
        for node, distance in graph[current]:
            if distance + distances[current] < distances[node]:
                distances[node] = distance + distances[current]
--fcc-editable-region--    
    print(f'Unvisited: {unvisited}\nDistances: {distances}\nPaths: {paths}')

#shortest_path(my_graph, 'A')
```
